DWG Workmode

DWG workmode is a working environment within MicroStation specifically adapted to the editing and reviewing of DWG files. MicroStation natively reads and writes both the MicroStation DGN file format and the DWG file format thus enabling less data loss from sharing. You can also directly reference a DWG file from a MicroStation DGN file.

When you open a DWG file in MicroStation, various MicroStation tools are restricted to ensure compatibility with the DWG format. When you are required to create DGN files that are DWG compatible, you can turn on DWG workmode. In both cases MicroStation restricts its tools to create only elements that are compatible with the DWG format.

The main purpose of the DWG workmode is to ensure that no DWG-incompatible features are added to the DWG file while editing it in MicroStation. This is done by restraining access to certain tools and features of MicroStation that remain unsupported in AutoCAD.

Raster Manager and the DWG workmode

Raster Manager has been adapted to the DWG workmode to best reflect the image attachment abilities of AutoCAD. Many features are common to both platforms, but some are only found in MicroStation. These features are disabled in MicroStation's DWG workmode. Some of the features that are affected are generic (for example, image file types available), and some are file type dependant (for example, various transparency settings).

Generic disabled features

When you operate in DWG workmode, the following functionality is disabled by default:

Auxiliary information

Any feature allowing to assign a logical name and description to image attachments is disabled in DWG mode.

Images from server

Raster Manager allows the attachment of images accessible through a ModelServer Imager or Bentley Publisher server. However, access to image servers has been blocked from the Raster Manager interface when working in DWG mode.

Display control of images

MicroStation allows to specify whether or not to display the images in a specific view port. This capability is disabled in DWG mode, so that Raster Manager will display the images in ALL views or in NO view at all.

Independent scale factor along the x- and y-axis

When modifying an image in MicroStation, it is possible to scale it along the x- and y-axis using two different scale factors. The feature is not available in DWG mode.

Image clipping

Raster Manager's mask clipping functionality is disabled in DWG mode.

Tint color

When working with images in DWG workmode, all tint related tools and dialog items are disabled.

Display gamma

The display gamma setting is made unavailable while in DWG workmode and has a default value of 1.00.

Print gamma

The print gamma setting is also made unavailable while in DWG mode and has a default value of 1.00.

Print control

In MicroStation, users can control the printing of an image through a toggle button in Raster Manager's main dialog box. This feature is not available in DWG workmode.

Raster Projects

When working in DWG Workmode, the ability to import Raster Manager Projects has been disabled.

Supported image file types

The following table lists the raster file formats supported in DWG workmode:

Type	Description and versions	File extension
BMP	Windows and OS/2 bitmap format	.bmp, .dib
CALS-1	Mils-R-Raster I	.Gp4, .mil, .rst, .gc4, .cal
ECW	ERMapper Compressed Wavelet format	.ecw
JFIF / JPEG	Joint Photograpics Expert Group	.jpg, .jpeg
PCX	Picture PC Paintbrush Picture	.pcx
PNG	Portable Network Graphic Run-Length Compressed	.png
RLC	Run-Length Compressed	.rlc
TARGA	True Vision Raster-Based Data Format	.tga
TIFF	Tagged Image File Format	.tif, .tiff

File type dependant disabled features

When you operate in DWG workmode, the following file type dependant functionality is affected:

Transparency settings

When dealing with transparency settings in Raster Manager, some features are specific to the image type (binary, continuous tone and 24-bit palette) and their behavior in DWG mode has been modified differently depending on the image type.

Binary images

When a binary image is attached in DWG workmode, the background transparency settings are disabled and the background transparency factor is set to 100%. The foreground transparency settings are also disabled and foreground transparency is set to 0.

Continuous tone and 24-bit images

The transparent settings for 24-bit, 8-bit and 4-bit images are also modified when working in DWG workmode. The transparent color picker is always disabled and the transparent factor/scale is disabled and set to 0.

When loading a DWG file, if the image's transparency display is ON, then the transparent toggle in Raster Manager will also be ON.

If the “fade” setting has been applied to the image from the DWG file, then this setting will be interpreted as transparency applied to all colors. The "all color transparent settings" will then never be disabled.

In order to see the effect of transparency on all colors, the transparent toggle must be ON. When an image has a “fade” setting greater than 0, but has its transparency OFF, then the image will automatically be displayed with transparency in MicroStation in order to see the effect of the fading.

Background color

Binary Images

All tools that relate to background color modifications in Raster Manager have been disabled.

Continuous tone and 24-bit images

This feature does not affect 24-bit, 8-bit and 4-bit images, since there is no concept of background and foreground for these types of images.

Troubleshooting DWG workmode

What happens if a DWG image is not located in the XY plane?

The placement of an image in any 3D plane is a supported feature for Raster Manager in MicroStation. Similar to AutoCAD, the rasters will display in any 3D plane as long as the “Apply Rotation and Affinity to Raster” toggle is turned ON (in the Display/Print tab of the Attachment Settings dialog box). This toggle is set to ON by default. If the toggle is set to OFF, the rotation and affinity values of the raster attachments are lost. This toggle allows compliancy with the way Raster Reference displayed rasters in MicroStation J.

Though 3D display is fully supported, some restrictions do apply for the modify, mirror, warp and clip functions. They require the rasters to be attached parallel to the DGN's X-Y plane in order to be effective in a 3D DGN. If the raster is not parallel to the X-Y plane, these functions will be disabled for raster manipulations.

What happens if an image has a self-intersecting clip polygon?

For the time being, when loading a DWG file with such a polygon, MicroStation ties this clip polygon to the image attachment, but the rendered image does not show clipping at all, even though the clipping data has been transferred. This is done so that no data is lost when switching from one platform to the other. On the other hand, if an image has a self-intersecting clip polygon and the user decides to set a new clip polygon on the image, the original (and invisible to the MicroStation user) clip boundary is deleted and replaced with the new one.

What happens with an unsupported image file type in MicroStation ?

When loading a DWG file containing an unsupported image file type in MicroStation, the image appears in Raster Manager's image list, but with the mention “Raster cannot be read.” Even though Raster Manager will allow the modification of this image's properties, the modifications will not be saved to the DWG file.

What happens if an image file cannot be found?

When loading an image file attached in a DWG file that cannot be found from the filename information contained in the DWG entity, the image also appears in Raster Manager's image list, but with the mention “Raster not found.” Because of its missing status, the image file type is unknown. When this happens, the image's color mode is forced to RGB. The same limitations on modifications stand when this case arises as when an unsupported image file type is loaded in MicroStation (i.e., no changes are recorded).